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1.
Anim Genet ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39291549

RESUMO

There is evidence that Murciano Granadina (MG), the most important caprine dairy breed in Spain, has been introgressed by African goats, but the precise geographic origin of such introgression has not been identified yet. Moreover, an accurate estimate of the magnitude of this African introgression is lacking, since current estimates are based on small numbers of sampled individuals. The aim of our work was to tackle these two issues by genotyping 500 MG goats with the Goat SNP50 BeadChip and comparing their genotypes with those of reference populations from Spain (Bermeya), France (Saanen), Morocco (Barcha, Draa, Ghazalia, Noire de Atlas, Nord, Moroccan), Egypt (Barki, Oasis, Saidi), Algeria (Arabia, Makatia, M'Zabite, Kabyle), Tunisia (Tunisian native breeds) and Sudan (Desert, Nilotic, Taggar). The population of 500 MG goats was subdivided into 10 datasets of 50 individuals to ensure that sample sizes of the target (MG) and reference populations are balanced. Performance of an unsupervised ADMIXTURE analysis demonstrated that MG goats have a North African ancestry, with an average proportion of 4.4 ± 2.3%. Next, we did a supervised ADMIXTURE analysis that revealed that the Moroccan genetic component reaches a proportion of 4.01 ± 3.9% in MG goats, while the Algerian (0.001 ± 0.001%), Egyptian (0.2 ± 0.1%), Sudanese (0.1 ± 0.1%) and Tunisian (0.3 ± 0.4%) components are present in extremely small proportions. The historical circumstances of this introgression event are currently unknown, but several plausible scenarios are outlined. Moreover, our results show considerable inter-individual heterogeneity regarding the magnitude of the Moroccan introgression of MG goats (0%- 12% depending on the MG data set under analysis). This result implies that reliable estimates about the introgression of autochthonous livestock by exotic breeds can only be obtained by extensively sampling target populations.

2.
Anim Genet ; 52(5): 683-693, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34196982

RESUMO

Artificial selection is one of the major forces modifying the genetic composition of livestock populations. Identifying genes under selection could be useful to elucidate their impact on phenotypic variation. We aimed to identify genomic regions targeted by selection for dairy and pigmentation traits in Murciano-Granadina goats. Performance of a selection scan based on the integrated haplotype score test in a population of 1183 Murciano-Granadina goats resulted in the identification of 77 candidate genomic regions/SNPs. The most significant selective sweeps mapped to chromosomes 1 (69.86 Mb), 4 (41.80-49.95 Mb), 11 (65.74 Mb), 12 (31.24 and 52.51 Mb), 17 (34.76-37.67 Mb), 22 (31.75 Mb), and 26 (26.69-31.05 Mb). By using previously generated RNA-Seq data, we built a catalogue of 6414 genes that are differentially expressed across goat lactation (i.e. 78 days post-partum, early lactation; 216 days post-partum, late lactation; 285 days post-partum, dry period). Interestingly, 183 of these genes mapped to selective sweeps and several of them display functions related with lipid, protein, and carbohydrate metabolism, insulin signaling, cell proliferation, as well as mammary development and involution. Of particular interest are the CSN3 and CSN1S2 genes, which encode two major milk proteins. Additionally, we found three pigmentation genes (GLI3, MC1R, and MITF) co-localizing with selective sweeps. Performance of a genome-wide association study and Sanger sequencing and TaqMan genotyping experiments revealed that the c.801C>G (p.Cys267Trp) polymorphism in the melanocortin 1 receptor (MC1R) gene is the main determinant of the black (GG or GC genotypes) and brown (CC genotypes) colorations of Murciano-Granadina goats.


Assuntos
Cabras/genética , Lactação/genética , Pigmentação/genética , Seleção Genética , Animais , Cruzamento , Feminino , Estudos de Associação Genética/veterinária , Genética Populacional , Genoma , Haplótipos , Proteínas do Leite/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Espanha
3.
J Dairy Sci ; 103(9): 8274-8291, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32564953

RESUMO

Improving knowledge on the causative polymorphisms or genes regulating the expression of milk quantitative and qualitative traits and their interconnections plays a major role in dairy goat breeding programs and genomic research. This information enables optimization of predictive and selective tools, to obtain better-performing animals to help satisfy market demands more efficiently. Goat milk casein proteins (αS1, αS2, ß, and κ) are encoded by 4 loci (CSN1S1, CSN1S2, CSN2, and CSN3) clustered within 250 kb on chromosome 6. Among the statistical methods used to identify epistatic interactions in genome-wide qualitative association studies (GWAS), gene-based methods have recently grown in popularity due to their better statistical power and biological interpretability. However, most of these methods make strong assumptions about the magnitude of the relationships between SNP and phenotype, limiting statistical power. Thus, the aims of this study were to quantify the epistatic relationships among 48 SNP in the casein complex on the expression of milk yield and components (fat, protein, dry matter, lactose, and somatic cells) in Murciano-Granadina goats, to explain the qualitative nature of the SNP used to quantify the genotypes produced as a result. Categorical principal component analysis (CATPCA) was used to delimit and group the number of SNP studied depending on their implications in the explanation of milk yield and components variability. Afterward, nonlinear canonical correlation analysis was used to identify relationships among and within the SNP groups detected by CATPCA. Our results suggest that 79.65% of variability in the traits evaluated may be ascribed to the epistatic relationships across and within 7 SNP groups. Two partially overlapping groups of epistatically interrelated SNP were detected: one group of 21 SNP, explaining 57.56% of variability, and another group of 20 SNP, explaining 42.43% (multiple fit ≥ 0.1). Additionally, SNP18, 32, and 36 (CSN1S2, CSN1S1, and CSN2 loci, respectively) were the most significant SNP to explain intragroup epistatic variability (component loading > |0.5|). Conclusively, milk yield and quality may not only depend on the specific casein gene pool of individuals, but may also be relevantly conditioned by the relationships set across and within such genes. Hence, studying epistasis in isolation may be crucial to optimize selective practices for economically important dairy traits.


Assuntos
Caseínas/genética , Epistasia Genética , Cabras/genética , Leite/metabolismo , Polimorfismo Genético/genética , Animais , Cruzamento , Feminino , Genótipo , Glicolipídeos/análise , Glicoproteínas/análise , Cabras/fisiologia , Lactose/análise , Gotículas Lipídicas , Leite/química , Proteínas do Leite/análise , Fenótipo
4.
Cryobiology ; 86: 33-39, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30611732

RESUMO

The aim of the present study was to evaluate the effect of the addition of different concentrations of two olive oil-derived antioxidants, hydroxytyrosol (3,4-dihydroxyphenylethanol, HT) and 3,4-dihydroxyphenylglycol (DHPG), on ovine semen during the freezing-thawing process. Sperm was collected, pooled and diluted with commercial extenders and then divided into aliquots supplemented with different concentrations (10 µg/ml, 30 µg/ml, 50 µg/ml and 70 µg/ml) of HT, DHPG and a mixture (MIX) of both antioxidants. A control group, without antioxidant, was also prepared. Sperm motility, viability, acrosome integrity, mitochondrial membrane potential and lipid peroxidation (LPO) were assessed. The results showed that frozen-thawed ram spermatozoa exhibited lower values for motility, membrane integrity, acrosome and mitochondrial membrane potential than fresh samples (P ≤ 0.01). However, when antioxidants were added, thawed spermatozoa exhibited relatively low LPO, recording values similar to fresh spermatozoa; by contrast, the control group of frozen-thawed spermatozoa without antioxidants exhibited significantly higher LPO (P ≤ 0.01). The addition of a HT+DHPG mixture (MIX) had a negative impact on sperm membrane and acrosome integrity, suggesting that a pure antioxidant supplementation has the potential to offer superior results. In conclusion, HT and DHPG exhibited a positive effect on the frozen-thawed spermatozoa inasmuch as they reduced the LPO. These olive oil-derived antioxidants have the potential to improve frozen-thawed sperm quality, although further studies should be carried out to analyse the antioxidant effect at different times after thawing.


Assuntos
Antioxidantes/farmacologia , Metoxi-Hidroxifenilglicol/análogos & derivados , Álcool Feniletílico/análogos & derivados , Preservação do Sêmen/métodos , Sêmen/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Acrossomo/efeitos dos fármacos , Animais , Criopreservação/métodos , Congelamento , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Potencial da Membrana Mitocondrial , Metoxi-Hidroxifenilglicol/farmacologia , Azeite de Oliva/farmacologia , Álcool Feniletílico/farmacologia , Análise do Sêmen , Ovinos
5.
Anim Genet ; 50(5): 501-511, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31393638

RESUMO

The population of Spanish sheep has decreased from 24 to 15 million heads in the last 75 years due to multiple social and economic factors. Such a demographic reduction might have caused an increase in homozygosity and inbreeding, thus limiting the viability of local breeds with excellent adaptations to harsh ecosystems. The main goal of our study was to investigate the homozygosity patterns of 11 Spanish ovine breeds and to elucidate the relationship of these Spanish breeds with reference populations from Europe, Africa and the Near East. By using Ovine SNP50 BeadChip data retrieved from previous publications, we have found that the majority of studied Spanish ovine breeds have close genetic relatedness with other European populations; the one exception is the Canaria de Pelo breed, which is similar to North African breeds. Our analysis has also demonstrated that, with few exceptions, the genomes of Spanish sheep harbor fewer than 50 runs of homozygosity (ROH) with a total length of less than 350 Mb. Moreover, the frequencies of very long ROH (>30 Mb) are very low, and the inbreeding coefficients (FROH ) are generally small (FROH  < 0.10), ranging from 0.008 (Rasa Aragonesa) to 0.086 (Canaria de Pelo). The low levels of homozygosity observed in the 11 Spanish sheep under analysis might be due to their extensive management and the high number of small to medium farms.


Assuntos
Homozigoto , Carneiro Doméstico/genética , Animais , Variação Genética , Genética Populacional , Polimorfismo de Nucleotídeo Único , Carneiro Doméstico/classificação , Espanha
6.
J Anim Breed Genet ; 134(4): 340-350, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28194814

RESUMO

Criollo horse populations descend from horses brought from the Iberian Peninsula over the period of colonization (15th to 17th century). They are spread throughout the Americas and have potentially undergone genetic hybridization with other breeds in the recent past. In this study, 25 autosomal microsatellites were genotyped in 50 horse breeds representing Criollo populations from 12 American countries (27 breeds), breeds from the Iberian Peninsula (19), one breed each from France and Morocco and two cosmopolitan horse breeds (Thoroughbred and Arabian). The genetic relationships among breeds identified five clusters: Celtic; Iberian; North American with Thoroughbred influence; most Colombian breeds; and nearly all other Criollo breeds. The group of "all other Criollo breeds" had the closest genetic relationship with breeds originating from the Iberian Peninsula, specifically with the Celtic group. For the whole set of Criollo breeds analysed, the estimated genetic contribution from other breeds was approximately 50%, 30% and 20% for the Celtic, Iberian and Arab-Thoroughbred groups, respectively. The spatial distribution of genetic diversity indicates that hotspots of genetic diversity are observed in populations from Colombia, Ecuador, Brazil, Paraguay and western United States, possibly indicating points of arrival and dispersion of Criollo horses in the American continent. These results indicate that Criollo breeds share a common ancestry, but that each breed has its own identity.


Assuntos
Variação Genética , Genética Populacional , Cavalos/genética , Repetições de Microssatélites , Animais , Cruzamento , Genótipo , Filogenia , Estados Unidos
7.
Heredity (Edinb) ; 117(1): 14-24, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27025169

RESUMO

Criollo pig breeds are descendants from pigs brought to the American continent starting with Columbus second trip in 1493. Pigs currently play a key role in social economy and community cultural identity in Latin America. The aim of this study was to establish conservation priorities among a comprehensive group of Criollo pig breeds based on a set of 24 microsatellite markers and using different criteria. Spain and Portugal pig breeds, wild boar populations of different European geographic origins and commercial pig breeds were included in the analysis as potential genetic influences in the development of Criollo pig breeds. Different methods, differing in the weight given to within- and between-breed genetic variability, were used in order to estimate the contribution of each breed to global genetic diversity. As expected, the partial contribution to total heterozygosity gave high priority to Criollo pig breeds, whereas Weitzman procedures prioritized Iberian Peninsula breeds. With the combined within- and between-breed approaches, different conservation priorities were achieved. The Core Set methodologies highly prioritized Criollo pig breeds (Cr. Boliviano, Cr. Pacifico, Cr. Cubano and Cr. Guadalupe). However, weighing the between- and within-breed components with FST and 1-FST, respectively, resulted in higher contributions of Iberian breeds. In spite of the different conservation priorities according to the methodology used, other factors in addition to genetic information also need to be considered in conservation programmes, such as the economic, cultural or historical value of the breeds involved.


Assuntos
Cruzamento , Repetições de Microssatélites , Suínos/genética , Alelos , Animais , Conservação dos Recursos Naturais , Evolução Molecular , Variação Genética , Genótipo
8.
J Anim Breed Genet ; 133(2): 155-64, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26364918

RESUMO

This study presents the first insights into the genetic diversity and structure of the American donkey metapopulation. The primary objectives were to detect the main structural features underlying variability among American donkey populations, identify boundaries between differentiated gene pools, and draw the main colonization pathways since the introduction of donkeys into America in the 15th century. A panel of 14 microsatellite markers was applied for genotyping 350 American donkeys from 13 countries. The genetic structure of this metapopulation was analysed using descriptive statistics and Bayesian model-based methods. These populations were then compared to a database containing information on 476 individuals from 11 European breeds to identify the most likely ancestral donor populations. Results showed the presence of two distinct genetic pools, with confluence of the two in Colombia. The southern pool showed a unique genetic signature subsequent to an older founder event, but lacked any significant influence of modern gene flow from Europe. The northern pool, conversely, may have retained more ancestral polymorphisms and/or have experienced modern gene flow from Spanish breeds. The Andalusian and, to a lesser extent, the Catalan breeds have left a more pronounced footprint in some of the American donkey populations analysed.


Assuntos
Equidae/genética , América , Animais , Teorema de Bayes , Equidae/classificação , Variação Genética , Genética Populacional
9.
Anim Genet ; 46(4): 452-6, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26153924

RESUMO

In the course of human migrations, domestic animals often have been translocated to islands with the aim of assuring food availability. These founder events are expected to leave a genetic footprint that may be recognised nowadays. Herewith, we have examined the mitochondrial diversity of goat populations living in the Canarian and Balearic archipelagos. Median-joining network analysis produced very distinct network topologies for these two populations. Indeed, a majority of Canarian goats shared a single ancestral haplotype that segregated in all sampled islands, suggesting a single founder effect followed by a stepping-stone pattern of diffusion. This haplotype also was present in samples collected from archaeological assemblies at Gran Canaria and Lanzarote, making evident its widespread distribution in ancient times. In stark contrast, goats from Majorca and Ibiza did not share any mitochondrial haplotypes, indicating the occurrence of two independent founder events. Furthermore, in Majorcan goats, we detected the segregation of the mitochondrial G haplogroup that has only been identified in goats from Egypt, Iran and Turkey. This finding suggests the translocation of Asian and/or African goats to Majorca, possibly as a consequence of the Phoenician and Carthaginian colonisations of this island.


Assuntos
DNA Mitocondrial/genética , Efeito Fundador , Genética Populacional , Cabras/genética , Animais , Animais Domésticos/genética , Pool Gênico , Deriva Genética , Haplótipos , Ilhas , Dados de Sequência Molecular , Análise de Sequência de DNA , Espanha
10.
J Anim Breed Genet ; 132(3): 268-76, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25823943

RESUMO

The Balearic sheep breeds, Mallorquina, Menorquina, Roja Mallorquina, Ibicenca and one possible new genetic group, Formentera, constitute a unique genetic resource in the Mediterranean farming landscape, displaying high genetic diversity levels and being well differentiated among themselves and with respect to the continental sheep breeds. We used a microsatellite panel of markers to study genetic diversity and relationships with other Spanish breeds. The results reported in this study have important implications for the use, conservation and breeding of Balearic sheep stocks. A mean number of 7.59 alleles was found among the Balearic sheep breeds for the microsatellites scored. The whole mean value of observed heterozygosity amounted to 0.62, whereas the expected heterozygosity value was 0.69, suggesting the presence of a great degree of genetic variability, although a significant deficit of heterozygotes was detected for some markers. Genetic distance estimates showed that Balearic sheep are differentiated from the other Spanish breeds and in particular, from the Merino type. The Ibicenca breed showed the highest distance value from other breeds. The neighbour-net method of analysis clustered the Roja Mallorquina, Menorquina and Mallorquina breeds. The Structure results clearly demonstrated the genetic differentiation among the four Balearic sheep breeds, with the Ibicenca and Formentera races joined, with slight migration among them. Few external genetic influences from the Spanish mainland breeds were detected.


Assuntos
Biodiversidade , Ovinos/genética , Animais , Variação Genética , Repetições de Microssatélites/genética , Ovinos/classificação
11.
Genet Mol Biol ; 38(1): 48-54, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25983624

RESUMO

In this study, we genetically characterized the Uruguayan pig breed Pampa Rocha. Genetic variability was assessed by analyzing a panel of 25 microsatellite markers from a sample of 39 individuals. Pampa Rocha pigs showed high genetic variability with observed and expected heterozygosities of 0.583 and 0.603, respectively. The mean number of alleles was 5.72. Twenty-four markers were polymorphic, with 95.8% of them in Hardy Weinberg equilibrium. The level of endogamy was low (FIS = 0.0475). A factorial analysis of correspondence was used to assess the genetic differences between Pampa Rocha and other pig breeds; genetic distances were calculated, and a tree was designed to reflect the distance matrix. Individuals were also allocated into clusters. This analysis showed that the Pampa Rocha breed was separated from the other breeds along the first and second axes. The neighbour-joining tree generated by the genetic distances DA showed clustering of Pampa Rocha with the Meishan breed. The allocation of individuals to clusters showed a clear separation of Pampa Rocha pigs. These results provide insights into the genetic variability of Pampa Rocha pigs and indicate that this breed is a well-defined genetic entity.

12.
J Dairy Sci ; 97(11): 7293-7, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25200789

RESUMO

Inferring the breed of origin of dairy products can be achieved through molecular analysis of genetic markers with a population-specific pattern of segregation. The goal of the current work was to generate such markers in goats by resequencing several pigmentation genes [melanocortin 1 receptor (MC1R), v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog (KIT), tyrosinase (TYR), and tyrosinase-related protein 2 (TYRP2)]. This experiment revealed 10 single nucleotide polymorphisms (SNP), including 5 missense mutations and 1 nonsense mutation. These markers were genotyped in 560 goats from 18 breeds originally from Italy, the Iberian Peninsula, the Canary Islands, and North Africa. Although the majority of SNP segregated at moderate frequencies in all populations (including 2 additional markers that were used as a source of information), we identified a c.764G>A SNP in MC1R that displayed highly divergent allelic frequencies in the Palmera breed compared with the Majorera and Tinerfeña breeds from the Canary Islands. Thus, we optimized a pyrosequencing-based technique that allowed us to estimate, very accurately, the allele frequencies of this marker in complex DNA mixtures from different individuals. Once validated, we applied this method to generating breed-specific DNA profiles that made it possible to detect fraudulent cheeses in which Palmero cheese was manufactured with milk from Majorera goats. One limitation of this approach, however, is that it cannot be used to detect illegal manufacturing where Palmero dairy products are produced by mixing milk from Palmera and Majorera goats, because the c.764G>A SNP segregates in both breeds.


Assuntos
Laticínios/análise , Marcadores Genéticos , Cabras/genética , Receptor Tipo 1 de Melanocortina/metabolismo , Animais , DNA/genética , Frequência do Gene , Genótipo , Mutação de Sentido Incorreto , Polimorfismo de Nucleotídeo Único , Receptor Tipo 1 de Melanocortina/genética , Sensibilidade e Especificidade , Análise de Sequência de DNA
13.
Genet Mol Res ; 12(2): 1119-31, 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23661437

RESUMO

The Uruguayan Creole cattle population (N = 600) is located in a native habitat in south-east Uruguay. We analyzed its genetic diversity and compared it to other populations of American Creole cattle. A random sample of 64 animals was genotyped for a set of 17 microsatellite loci, and the D-loop hyper-variable region of mtDNA was sequenced for 28 calves of the same generation. We identified an average of 5.59 alleles per locus, with expected heterozygosities between 0.466 and 0.850 and an expected mean heterozygosity of 0.664. The polymorphic information content ranged from 0.360 to 0.820, and the global FIS index was 0.037. The D-loop analysis revealed three haplotypes (UY1, UY2 and UY3), belonging to the European matriline group, with a haplotype diversity of 0.532. The history of the population, changes in the effective population size, bottlenecks, and genetic drift are possible causes of the genetic variability patterns that we detected.


Assuntos
DNA Mitocondrial/genética , Variação Genética , Repetições de Microssatélites/genética , Alelos , Animais , Cruzamento , Bovinos , Evolução Molecular , Frequência do Gene , Genética Populacional , Haplótipos , Filogenia
14.
Anim Genet ; 43(1): 2-10, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22221019

RESUMO

Genetic diversity in and relationships among 26 Creole cattle breeds from 10 American countries were assessed using 19 microsatellites. Heterozygosities, F-statistics estimates, genetic distances, multivariate analyses and assignment tests were performed. The levels of within-breed diversity detected in Creole cattle were considerable and higher than those previously reported for European breeds, but similar to those found in other Latin American breeds. Differences among breeds accounted for 8.4% of the total genetic variability. Most breeds clustered separately when the number of pre-defined populations was 21 (the most probable K value), with the exception of some closely related breeds that shared the same cluster and others that were admixed. Despite the high genetic diversity detected, significant inbreeding was also observed within some breeds, and heterozygote excess was detected in others. These results indicate that Creoles represent important reservoirs of cattle genetic diversity and that appropriate conservation measures should be implemented for these native breeds in order to minimize inbreeding and uncontrolled crossbreeding.


Assuntos
Bovinos/genética , Variação Genética , Repetições de Microssatélites , Animais , Linhagem
15.
J Anim Breed Genet ; 129(1): 79-87, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22225587

RESUMO

Brazilian goat breeds are believed to derive mainly from animals brought by Portuguese settlers since the 16th century. We used microsatellite markers in a sample of 436 animals to study genetic variability and differentiation of the six Portuguese (PT) and six Brazilian (BR) goat breeds currently recognized in the two countries. These breeds were also compared with an outgroup represented by a sample of Alpine (ALP) goats. The effective number of alleles and allelic richness were slightly higher in PT than in BR breeds. The global F(ST) was nearly 0.11 when PT and BR breeds were considered, with a mean pairwise F(ST) of about 0.03 among PT breeds, 0.07 among BR breeds and 0.15 between PT and BR breeds. The dendrogram illustrating relationships between populations and the correspondence analysis indicate the existence of two very distinct clusters, corresponding to the countries of origin of the breeds studied, which are nearly equidistant from the Alpine outgroup. The analysis with structure confirmed the separation between PT and BR breeds but suggests that some BR breeds, especially Graúna and Canindé, may share a common ancestry with PT breeds. The divergence observed between PT and BR breeds may result from founder effects and genetic drift but could also reflect the introduction in Brazil of goats originating from other regions, e.g., West Africa.


Assuntos
Deriva Genética , Cabras/genética , Animais , Oceano Atlântico , Brasil , Frequência do Gene , Loci Gênicos/genética , Variação Genética , Heterozigoto , Repetições de Microssatélites/genética , Portugal
16.
Biochem Genet ; 49(7-8): 523-32, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21373989

RESUMO

Agouti signaling protein (ASIP) is one of the key players in the modulation of hair pigmentation in mammals. Binding to the melanocortin 1 receptor, ASIP induces the synthesis of phaeomelanin, associated with reddish brown, red, tan, and yellow coats. We have sequenced 2.8 kb of the goat ASIP gene in 48 individuals and identified two missense (Cys126Gly and Val128Gly) and two intronic polymorphisms. In silico analysis revealed that the Cys126Gly substitution may cause a structural change by disrupting a highly conserved disulfide bond. We studied its segregation in 12 Spanish and Italian goat breeds (N = 360) with different pigmentation patterns and found striking differences in the frequency of the putative loss-of-function Gly(126) allele (Italian 0.43, Spanish Peninsular 0.08), but we did not observe a clear association with coat color. This suggests that the frequency of this putative loss-of-function allele has evolved under the influence of demographic rather than selection factors in goats from these two geographical areas.


Assuntos
Proteína Agouti Sinalizadora/genética , Cabras/genética , Cor de Cabelo/genética , Polimorfismo Genético , Substituição de Aminoácidos , Animais , Frequência do Gene , Itália , Espanha
17.
Zoo Biol ; 30(4): 399-411, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-20853411

RESUMO

The African antelope Addax nasomaculatus is a rare mammal at high risk of extinction, with no more than 300 individuals in the wild and 1,700 captive animals distributed in zoos around the world. In this work, we combine genetic data and genealogical information to assess the structure and genetic diversity of a captive population located at Parque Lecocq Zoo (N=27), originated from only two founders. We amplified 39 microsatellites previously described in other Artiodactyls but new to this species. Seventeen markers were polymorphic, with 2-4 alleles per locus (mean=2.71). Mean expected heterozygosity (He) per locus was between 0.050 (marker ETH3) and 0.650 (marker D5S2), with a global He of 0.43. The mean inbreeding coefficient of the population computed from pedigree records of all registered individuals (N=53) was 0.222. The mean coancestry of the population was 0.298 and F(IS) index was -0.108. These results reflect the importance of an adequate breeding management on a severely bottlenecked captive population, which would benefit by the incorporation of unrelated individuals. Thanks to the successful amplification of a large number of microsatellites commonly used in domestic bovids, this study will provide useful information for the management of this population and serve as future reference for similar studies in other captive populations of this species.


Assuntos
Animais de Zoológico , Antílopes/genética , Criação de Animais Domésticos , Animais , Conservação dos Recursos Naturais , Feminino , Variação Genética , Masculino , Repetições de Microssatélites , Linhagem , Uruguai
18.
Anim Genet ; 41(2): 128-41, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19817725

RESUMO

The ancestry of New World cattle was investigated through the analysis of mitochondrial and Y chromosome variation in Creoles from Argentina, Brazil, Mexico, Paraguay and the United States of America. Breeds that influenced the Creoles, such as Iberian native, British and Zebu, were also studied. Creoles showed high mtDNA diversity (H = 0.984 +/- 0.003) with a total of 78 haplotypes, and the European T3 matriline was the most common (72.1%). The African T1a haplogroup was detected (14.6%), as well as the ancestral African-derived AA matriline (11.9%), which was absent in the Iberian breeds. Genetic proximity among Creoles, Iberian and Atlantic Islands breeds was inferred through their sharing of mtDNA haplotypes. Y-haplotype diversity in Creoles was high (H = 0.779 +/- 0.019), with several Y1, Y2 and Y3 haplotypes represented. Iberian patrilines in Creoles were more difficult to infer and were reflected by the presence of H3Y1 and H6Y2. Y-haplotypes confirmed crossbreeding with British cattle, mainly of Hereford with Pampa Chaqueño and Texas Longhorn. Male-mediated Bos indicus introgression into Creoles was found in all populations, except Argentino1 (herd book registered) and Pampa Chaqueño. The detection of the distinct H22Y3 patriline with the INRA189-90 allele in Caracú suggests introduction of bulls directly from West Africa. Further studies of Spanish and African breeds are necessary to elucidate the origins of Creole cattle, and determine the exact source of their African lineages.


Assuntos
Bovinos/genética , DNA Mitocondrial/genética , Cromossomo Y , Animais , Feminino , Masculino , Mitocôndrias/genética , Polimorfismo Genético
19.
Res Vet Sci ; 126: 213-226, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31610472

RESUMO

Multiple births or twinning in equids are dangerous, undesirable situations that compromise the life of the dam and resulting offspring. However, embryo vitrification and freezing techniques take advantage of individuals whose multiple ovulations allow flushing more fertilised embryos from the oviduct to be collected, increasing the productivity and profitability of reproductive techniques. Embryo preservation is especially important in highly endangered populations such as certain donkey (Equus asinus) breeds; for which conventional reproductive techniques have previously been deemed inefficient. For instance, becoming an effective alternative to artificial insemination with frozen semen to preserve the individuals' genetic material. The objective of this study was to examine the historical foaling records of Andalusian donkeys to estimate prevalence, risk factors, phenotypic and genetic parameters for multiple births, assessing the cumulative foal number born per animal, maximum foal number per birth and multiple birth number per animal. We designed a Bayesian General Animal Mixed Model with single records considering the 'fixed' effects of birth year, birth season, birth month, sex, farm, location, and husbandry system. Age was considered and included as a linear and quadratic covariate. Gibbs sampling reported heritability estimates ranging from 0.18 ±â€¯0.101 to 0.24 ±â€¯0.078. Genetic and phenotypic correlations ranged from 0.496 ±â€¯0.298 to 0.846 ±â€¯0.152 and 0.206 ±â€¯0.063 to 0.607 ±â€¯0.054, respectively. Predicted breeding values obtained enable the potential selection against/for these traits, offering a new perspective for donkey breeding and conservation.


Assuntos
Equidae/fisiologia , Fertilidade/genética , Hereditariedade , Tamanho da Ninhada de Vivíparos/genética , Prole de Múltiplos Nascimentos/genética , Animais , Teorema de Bayes , Espécies em Perigo de Extinção , Equidae/genética , Feminino , Masculino , Modelos Genéticos , Fatores de Risco
20.
Animal ; 12(10): 2017-2026, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29306351

RESUMO

Goats have played a key role as source of nourishment for humans in their expansion all over the world in long land and sea trips. This has guaranteed a place for this species in the important and rapid episode of livestock expansion triggered by Columbus' arrival in the Americas in the late 1400s. The aims of this study are to provide a comprehensive perspective on genetic diversity in American goat populations and to assess their origins and evolutionary trajectories. This was achieved by combining data from autosomal neutral genetic markers obtained in more than two thousand samples that encompass a wide range of Iberian, African and Creole goat breeds. In general, even though Creole populations differ clearly from each other, they lack a strong geographical pattern of differentiation, such that populations of different admixed ancestry share relatively close locations throughout the large geographical range included in this study. Important Iberian signatures were detected in most Creole populations studied, and many of them, particularly the Cuban Creole, also revealed an important contribution of African breeds. On the other hand, the Brazilian breeds showed a particular genetic structure and were clearly separated from the other Creole populations, with some influence from Cape Verde goats. These results provide a comprehensive characterisation of the present structure of goat genetic diversity, and a dissection of the Iberian and African influences that gave origin to different Creole caprine breeds, disentangling an important part of their evolutionary history. Creole breeds constitute an important reservoir of genetic diversity that justifies the development of appropriate management systems aimed at improving performance without loss of genomic diversity.


Assuntos
Cruzamento , Variação Genética , Cabras , Animais , Brasil , Marcadores Genéticos , Cabras/genética , Filogenia
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